This application claims the priority benefit of Taiwan application serial no. 91137637, filed on Dec. 27, 2002.
1. Field of Invention
The present invention generally relates to a panel display and a manufacturing method thereof, and more particularly, to an optical interference type panel and a manufacturing method thereof.
2. Description of Related Art
Thin and light-weight panel displays, such as a liquid crystal display (LCD), organic emitting diode (OLED) and plasma display panels (PDP) have been widely used in daily life now. Wherein, LCD is gradually becoming the mainstream of the display. However, LCD still has disadvantages, such as the view angle not being wide enough, the response time not being fast enough, the full-color being implemented by using the color filters, and the polarizer being mandatory which causes the problem of poor efficiency of utlization of the light source and the problem of the backlight module""s consumption of more power.
An optical interference type panel has been currently developed., consisting primarily in a plurality of optical interference modulators arranged in array. The optical interference modulator primarily consists of a transparent electrode, a reflective electrode, and a supporting layer that supports the reflective electrode. With the support from the supporting layer, a specific air gap exists between the reflective electrode and the transparent electrode. After a light emits into the optical interference modulator via the transparent electrode, the light passes through the air gap and emits onto the second electrode. Then, the light is reflected from the second electrode via the transparent electrode. Since the light experiences different levels of interference in different air gaps, it shows light with different colors, e.g. a red light, a green light, and a blue light. Moreover, the reflective electrode in the optical interference modulator has to bind with the micro electro mechanical system (MEMS) for performing its design, so that the optical interference modulator can be switched between the on/off state and the objective of displaying can be achieved.
The optical interference type panel constituted by the optical interference modulators mentioned above is able to display appropriate color images without having to configure the color filters and the polarizer, so that the cost of the color filters can be saved. Moreover, the optical interference type panel constituted by the optical interference modulators mentioned above is also characterized by its low power consumption, fast response time, and being bi-stable. Therefore, it is advantageous for development of low power consumption products, such as the mobile phone, personal digital assistant (PDA), and e-book.
FIG. 1A to 1F schematically shows a sectional view of a manufacturing process for a conventional optical interference type panel. First, referring to FIG. 1A. a patterned first electrode layer 102, an optical film 103, and a sacrificial layer 104 are formed on a transparent layer 100. Wherein, the sacrificial layer 104 is made of a material of opaque molybdenum (Mo) or an alloy of molybdenum (Mo). Then, referring to FIG. 1B, a supporting material layer 106 and a negative type photoresist layer 108 are sequentially formed on the sacrificial layer 104. Then, referring to FIG. 1C, a backside expose process 110 and a develop process are performed by using the opaque sacrificial layer 104 as a mask to pattern the photoresist layer 108a. Then, referring to FIG. 1D, portion of the supporting layer 106 that are not covered by the photoresist layer 108a is removed by using the photoresist layer 108a as an etch mask, so as to form a supporting layer 106a. Then, referring to FIG. 1E, the photoresist layer 108a is removed, and a second electrode 112 is formed on the supporting layer 106a and the sacrificial layer 104 between the adjacent supporting layers 106a. Then, referring to FIG. 1F, a release process is performed, in which the XeF2 gas is used as an etch, so that the sacrificial layer 104 is converted into a gas and is removed, so as to form a optical interference type panel constituted by a plurality of optical interference modulators that are arranged in array.
However, in the manufacturing method for the optical interference type panel mentioned above, the sacrificial layer 104 must be made of an opaque material, and must be removed by the release process. Therefore, the qualified material is limited, requiring the choice of molybdenum (Mo) or the alloy of molybdenum (Mo). However, using a lot of molybdenum (Mo) or an alloy of molybdenum (Mo) to form the sacrificial layer as mentioned above significantly increases the manufacturing costs.
To solve the problem mentioned above, the objective of the present invention is to provide an optical interference type panel and a manufacturing method thereof, so as to reduce the manufacturing costs of the optical interference type panel.
A further objective of the present invention is to provide an optical interference type panel and a manufacturing method thereof, so as to simplify the manufacturing process of the optical interference type panel.
A manufacturing method for optical interference type panel is provided by the present invention. A patterned supporting layer is formed on a transparent substrate, a first electrode layer is subsequently formed on the supporting layer and the transparent substrate, and then an optical film is formed on the first electrode layer. Then, a sacrificial layer is formed on the optical layer between the adjacent supporting layers. Wherein, the sacrificial layer formed is below the optical film above the supporting layer. Then, a second electrode layer is formed on the sacrificial layer between the adjacent supporting layers and portion of the optical film. Afterwards, the sacrificial layer is removed.
Moreover, according to the present invention, a sacrificial material layer may be formed on the optical film, and a portion of the sacrificial material layer is removed to expose the optical film above the supporting layer to form a sacrificial layer. Wherein, the sacrificial layer is below the optical film above the supporting layer.
Furthermore, according to the present invention, after the sacrificial material layer is formed, a backside exposure process may be processed by using the supporting layer as a mask so as to expose the optical film above the supporting layer.
The optical interference type panel provided by the present invention primarily comprises a transparent substrate, a patterned supporting layer, a first electrode, an optical film, and a second electrode. Wherein, the supporting layer is located on the transparent substrate. The first electrode is located on the transparent substrate and the supporting layer. The optical film is located on the first electrode, and the edge of the second electrode is located on portion of the optical film above the adjacent supporting layer.
From the preferred embodiment of the present invention mentioned above, the optical interference type panel of the present invention first forms the opaque supporting layer, and then sequentially forms the first electrode layer, the optical film, and the transparent sacrificial layer that is made of the photo resistant material. Moreover, the sacrificial layer may be made of material that is low cost and is suitable for the release process. Therefore, using molybdenum (Mo) or the alloy of molybdenum (Mo) to form the sacrificial layer is not mandatory, so that the manufacturing costs for the optical interference type panel are reduced.
Moreover, the optical interference type panel of the present invention directly uses the photoresist material to form the sacrificial layer. Therefore, the present invention is able to avoid the step of coating a photoresist layer on the supporting layer that is required in the prior art, so that the manufacturing process of the optical interference type panel is simplified.
Furthermore, according to the present invention, after the sacrificial material layer is formed on the optical film, the backside exposure process can be avoided, and the etch method can be directly applied to form the sacrificial form. Therefore, the manufacturing process of the optical interference type panel is further simplified.
In addition, according to the present invention, the sacrificial layer that is below the optical film above the supporting layer can be directly formed on the optical film between the adjacent supporting layers. Therefore, the manufacturing process of the optical interference type panel is further simplified.